Subsurface structure of the Evershed flows in sunspots |
Auteur | Kitiashvili Irina |
Institution | HEPL, Stanford University |
Theme | Convection, dynamo and flows |
| Auteur(s) supplémentaire(s) | A.G. Kosovichev^1, N.N. Mansour^2, A.A. Wray^2 |
| Institution(s) supplémentaire(s) | 1 HEPL, Stanford University, USA, 2 NASA Ames Research Center, USA |
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Abstract | The radial outflows in sunspot penumbrae, known as the Evershed effect, are of significant interest for understanding the dynamics of sunspots. Local helioseismology has not been able to determine the depth of these flows and their relationship to the mass circulation in sunspots. Recent radiative MHD simulations have provided a convincing explanation of the Evershed flows as a natural consequence of magnetoconvection in the strongly inclined magnetic field of the penumbra. The simulations reproduce many observational features of the penumbra dynamics, including the filamentary structure, the high-speed non-stationary "Evershed clouds", as well as the "sea-serpent" behavior of magnetic field lines. We present the subsurface structure of the Evershed flows, obtained from the numerical simulations, determine the depth of the radial outflows for various magnetic field strengths and inclination, and describe the oscillation spectrum in regions of strong inclined magnetic fields. |
